DETECTION OF THE LIPID-PEROXIDATION PRODUCT MALONALDEHYDE IN RAT-BRAIN IN-VIVO

The extracellular concentrations of the lipid peroxidation product mal onaldehyde (MDA) and the antioxidants ascorbic and uric acid were meas ured in rat brain in vivo using microdialysis coupled to HPLC with ult ra violet spectrophotometry. Treatment with kainic acid at pH 4.1 (50 nmol) caused a significant increase in the sampled concentration of MD A but no significant changes in the antioxidants. Treatment with the s ame dose of kainic acid at pH 7.2 did not cause a significant increase in MDA, although some changes were noted in the antioxidants. The pap er demonstrates the ability to monitor changes of a lipid peroxidation breakdown product as a measure of oxidative stress in vivo. Furthermo re, the data suggests that the toxic action of kainic acid in acute pr eparations may be due to the elevation of hydrogen ions.